Rear mounted cable plow assembly

ABSTRACT

A CABLE PLOW ASSEMBLY IS DISCLOSED CARRIED BY A TRACTOR IN A CLOSELY COUPLED MANNER FOR ADVANTAGEOUS PURPOSES. THE EARTH PENETRATING BLADE OF THE PLOW IS POSITONABLE UP AND DOWN WITHIN A GUIDE BOX ASSEMBLY. ROLLER ASEMBLIES CARRIED BY BOTH THE BLADE AND THE GUIDE BOX ASSEMBLY FACILITATE VERTICAL ADJUSTMENT OF THE BLADE IN SAID ASSEMBLY. HYDRAULIC CYLINDERS POSITION THE BLADE. BLADE RETENTION MEANS WHICH INCLUDES THE ROLLER ASSEMBLIES SUPPORTS THE BLADE AGAINST HORIZONTAL LOADS INCIDENT TO CABLE LAYING.

Oct. 12, 1971 G BRlGHT EI'AL 3,611,596

REAR MOUNTED CABLE PLOW ASSEMBLY Filed Oct. 31, 1969 2 Sheets-Sheet 1 INVENTORQ KENNETH e. BRIGHT mas o. STANDLEY AGENT Oct. 12, 1971 H- Em 3,611,596

REAR MOUNTED CABLE PLOW ASSEMBLY Filed Oct. 31, 1969 2 Sheets-Sheet 2 3,611,596 REAR MOUNTED CABLE PLOW ASSEMBLY Kenneth G. Bright, Camas Valley, and Miles 0. Standley, Pilot Rock, reg.; said Bright assignor to Henkels and McCoy, Inc, Blue Bell, lPa. Filed Oct. 31, 1969, Ser. No. 872,853

lint. Cl. E02f 5/18 Us. or. 37-193 3 Claims ABSTRACT OF THE DISCLOSURE A cable plow assembly is disclosed carried by a tractor in a closely coupled manner for advantageous purposes. The earth penetrating blade of the plow is positionable up and down within a guide box assembly. Roller assemblies carried by both the blade and the guide box assembly facilitate vertical adjustment of the blade in said assembly.

Hydraulic cylinders position the blade. Blade retention means which includes the roller assemblies supports the blade against horizontal loads incident to cable laying.

BACKGROUND OF THE INVENTION ing of the entire cable plow assembly usually by means of hydraulic cylinders. Further, the blade itself may be positionable and lockable within its holder to provide for additional vertical positioning. Continuing it is the general practice to incorporate a steering cylinder or cylinders coupled to the blade holder to urge the blade about an upright axis to facilitate turning of the prime mover. The aforementioned attaching draft members or arms are necessarily of several feet in length to provide the desired vertical travel of the blade and blade holder. The linkage so provided results in a plow blade positioned a considerable distance rearward of the effective turning point of the tractor located at the vehicle center. To avoid incurring damaging side loads on the blade during turning of the tractor existing linkages incorporate the above mentioned steering cylinder(s) which are actuated in a coordinated manner with the vehicle steering controls.

In the US. patent to Hinkel et al., No. 3,140,745 issued July 14, 1964 this problem was considered and a solution tendered in the form of an arrangement whereby tractor steering was accomplished by a blade coupled cylinder. The distance the blade is offset from the tractors turning point becomes a major factor in determining tractor maneuverability. With existing draft members or arms the distance is such that a steering cylinder must be utilized. Further a degree of operator skill is necessary to coordinate such cylinders use with the tractors steering controls. Additionally close operator surveillance of the plow blade is a desirable feature of the present invention. Consideration has been given in the present invention to remedying additional disadvantages inherent in the locating of a cable plow of substantial distance from the chasis of the prime mover tractor. This additional problem concerns the undesirable variance in ground penetration of the plow blade resulting from pitching of the tractor while traversing rough terrain. The operating depth of the blade during pitching of the tractor, will vary proportionately with the distance the blade is longitudinally olfset behind United States Patent the tractor. As aforesaid conventional cable plow attachment linkages are of a considerable length making constant blade positioning a necessity in rough terrain. The pitching movement of a tractor about its traverse axis which may be common to the rear wheels thereof, will result in irregular burial depth of the conduit. Since most all cable laying is done within specified criteria the depth must be considered critical in performance of the job. It follows from the foregoing that a highly desirable feature of a cable plow is that it be closely coupled to the prime mover both when considering blade penetration and as earlier stated, turning of the tractor. The present cable plow achieves these objects.

A further advantage resides in the capability of the plow blade to move up and down while bearing substantial horizontally directed loads. 7

Additional to the turning problems resulting from existing elongate draft members and associated linkages is the matter of convenient transport to a work site. Existing cable plow and tractor combinations by reason of their length require the use of special trailer equipment. The present cable plow assembly is of a compact nature allowing transport by ordinary tractor hauling equipment.

SUMMARY OF THE INVENTION The present cable plow assembly incorporates an upright ground penetrating blade vertically positionable by hydraulic cylinders within a guide box housing. The housing is trailed closely adjacent the tractor chasis for swinging movement about an upright axis. The blade is supported in its guide box against draft loads by plural roller means mutually carried by and interengaging said blade and guide box. The means so provided are fully engageable throughout the full travel of the blade. Hydraulic cylinders vertically position the blade which need not be mechanically locked or pinned within its holder as is conventionally done with inserted pins or bolts extending transversely through both the blade and housing.

It is an important object of the present plow assembly to provide a ground penetrating plow blade in close disposition to its supporting vehicle to reduce adverse side loading on the blade and correspondingly permit normal tractor maneuverability. Important is the dispensing of the elongate draft members and associated linkage heretofor necessary for vertical travel. The present plow blade is operable at various depths at a constant angular relationship to the ground. Other plow assemblies by reason of necessarily being positionable on an extended radius do not retain a constant relationship with the ground, the an-gularity being pre-set for the most commonly plowed depth. Some plow assemblies utilize a pitch adjusting cylinder for fore and aft tilting of the blade to achieve a desired rake angle.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a side elevational view of a prime mover with the present invention trailed therebehind.

FIG. 2 is an enlarged side elevational view of the present cable plow assembly with parts broken away for illustrative purposes,

FIG. 3 is a front elevational view taken along line 3-3 of parent FIG. 2,

FIG. 4 is a sectional plan view taken downwardly along irregular line 4l4 of FIG. 3 which in turn is related to FIG. 2,

FIG. 5 is a side elevational view of the upper portion of the cable plow blade,

FIG. 6 is a plan view of FIG. 5,

FIG. 7 is a horizontal view taken approximately along line 77 of FIG. 5, r

vroller construction, and

FIG. 13 is a plan view of the lower hinge bracket ,taken along line 1313 of FIG. 8.

DESCRIPTION OF PREFERRED EMBODIMENT With continuing reference to the drawings wherein applied reference numerals indicate parts similarly indentifiedin the following specification, the reference numeral 1 indicates a track equipped tractor serving to mount the present invention. The tractor may, for purposes of convenience, be of the type having forwardly extending positionable arms at 2 upon which a cable reel (not shown) can be supported for transport.

The instant invention resides in the cable plow assembly indicated generally at 3 which, as shown, is in closeproximity to the rear end of the tractor. The earth cutting blade indicated at 4 is vertically positionable, as later described, to cut a kerf of a specified depth or oppositely. may be raised away from the ground surface. A toe portion 5 is formed on the blade to assist in overcoming the blades tendency to rise during trench cutting. Swingably trailed from the blade 4 is a cable shoe 6 which guides the cable C passing therethrough into place within the trench or kerf cut. A shaft 7 is removable to permit shoe removal to allow the blade to function alone as a ripping tool where pre-ripping passes are necessary prior to the final cable laying pass.

I Mounting the tooth is a tooth guide box assembly generally at 10 which assembly houses the tooth and guides same during vertical positioning. The guide box assembly comprises four elongate upright plates in two pairs at 11 and 12 in parallel juxtaposed relationship to opposite sides of the blade. The forward pair at 11 are interconnected by a spacer bar 13 running lengthwise intermediate the plates forward edges. The pairs of plates are additionally retained in spaced apart relationship by an upper tie bar 14, best seen in FIG. 9, while adjacent the plates lower portions upper and lower hinge brackets 15 and 16 also interconnect the pairs of plates. FIG. 4 shows the upper hinge bracket having open areas 17 for hydraulic cylinder passage while bridging together and retaining the pairs of upright plates.

The lower hinge bracket 16 in FIG. 13 also supports the pairs of guide assembly plates by means of rectangular members 18 welded within a central bifurcation 20 in said lower bracket. Further, the bracket 16 mounts clevises 21 Within which the lower ends of the blade lift cylinders are retained as at 22. Both hinge brackets are open aft of the blade to permit vertical passage of the cable shoe.

.Each hinge bracket defines at its forward end a pin receiving openings through which pivot pins 19 depend, the axis of the pins constituting an upright axis A for plow assembly swinging movement. Ears carried by a tractor mounted plate complete the attachment of the plow assembly to the tractor.

To secure the blade against horizontal displacement within the guide box assembly during a trench forming operation blade retention means are provided. The retention means further serve to guide the blade during vertical movement in a path parallel to the upright axis of said assembly. Comprising the blade retention means are cooperating components hereafter described carried by both the guide box assembly and the blade 4 itself. Affixed'along the outer surfaces of the pairs of plates 11- 12 as best shown in FIGS. 8 and 11, are pairs of guide bars 23-24 each pair being horizontally spaced to receive a blade carried roller later described, which is confined for vertical travel therebetween. Each bar 23-24 is securely mounted to its supporting plate 11-12 preferably by a series of bolts 25 to allow bar replacement. Reinforcing each pair of guide bars is a tie plate 26 bolted securely at 27 along and to the underlaying guide bars. Of practical interest, plows embodying the present invention have advantageously utilized bars of forty-seven inch length to provide a vertical blade travel of approximately forty-five inches.

With continuing reference to blade retention means the plates 11-12 of the guide box assembly serves to rotatably mount pairs of guide box roller assemblies 30 one each carried by the plates. In similarity to the above mentioned guide bars, the roller assemblies also cooperate with blade carried components to support the blade during vertical blade travel. In FIG. 12. details of a roller assembly 30 are shown, such being typical of all of said assemblies and description of one will suflice for all. A stub shaft 31 is inset at its inner end within an aperture in the plate 12 and secured by a flush weldment 32about its chamfered periphery. A flange 33 thereon spaces an inner race 34 of a hearing from the plate. The outer race at 35 carries a roller shell 36 which is in rolling contact with a later described blade carried component. A retainer ring 37 for the outer race cooperates with a shoulder 36A on the roller shell to retain the shell on the outer race. Completing the roller assembly is an annular ring 38 in retaining contact with the inner race 34, said ring being carried by a roller assembly brace plate 40 which interconnects the stub shafts 31 of pairs of roller assemblies. A bolt 41 is received in a control threaded bore in the stub shaft.

The elongate blade, as aforesaid, is adapted to be moved vertically within the guide box assembly with a portion of the blade retention means being carried thereon and cooperable with the above mentioned components. As shown best in FIGS. 5 and 7 a blade roller assembly 42 is mounted thereon approximately mid-way of the blades length, the roller shells being confined for travel intermediate the guide bars 23-24. The blade roller assembly comprises a roller mounting shaft 45 medially disposed through the blade in a corresponding aperture 4A. The shaft is shouldered at 45A which abuts one side of the blade 4, while oppositely a nut element 46 is in place on a threaded segment 45B of the shaft. The bearings associated with the lower blade roller assembly include inner races 47 while outer bearing races 48 carry roller shells 50 on opposite sides of the blade 4. Internal snap rings 51 space apart the outer races while the inner races are retained by external snap rings 52 adjacent the shaft ends. From this it will be evident that the laterally carried roller shells 50 each having rolling contact with the guide bars 23-24 with approxi: mately .050 of an inch overall clearance existing between the roller shells and their associated guide bars.

Additional blade retention means are carried by the blade 4 such being in the form of blade bars 54 op positely mounted on the sides of the blade for contact with the above described guide box rollers 30. The blade bars 54 may be secured by transversely extending bolts 49 the ends of which terminate within sockets or recesses 54A in the bar. The blade bars travel within that area intermediate the plates 11 and 12. The upper tie bar 14 for the plates defines inset area 14A (FIG. 9) to permit upward passage of the bars. Clearance between the blade bars and the cooperating guide box rollers 30 is substantially same as earlier mentioned in connection with the blade roller assembly 50 and the guide bars 23-24.

From the above description of the blade retention means it will be seen that throughout the vertical positionable travel of the tooth for a different cable burying depths the bar and roller assembly components function to receive horizontally directed loads during a plowing operation. Ultimately the load is transferred to the guide box assembly 10.

For varying the operational depth of the blade, a pair of double acting hydraulic cylinders 55 are mounted as aforesaid at 22 within the clevises 21. The piston rods 56 of the cylinders terminate in rod ends 57 which receive a crosstree 58 transversely disposed through the upper end of the blade. FIG. 4 shows details of the cross tree 58 which includes a tube member 60 welded in place within a blade opening 61 and having a shaft 62 extending through said member to receive the rod ends. The hydraulic cylinders 55 should provide rod end travel of approximately forty-five inches to achieve the opera-. tional depths and ground clearance earlier noted. For uniform control of the cylinders a branched hydraulic line (not shown) connects the cylinders upper ends with a three way valve control while similarly the lower ends of the cylinder are in branched communication with the control. Accordingly the plow blade is set at the required plowing depth with the valve control then moved to its hold position wherein fluid is held above and below the piston of each cylinder.

Mounted at the blades upper end is a fairlead device 63 having cable carrying rollers 64 therein disposed arcuately to support the cable C prior to its downward passage through the cable shoe.

The operation of the present cable plow assembly is believed apparent from the foregoing description. The load imposed on the blade during cable laying is for the most part horizontally oriented. The forward edge of the blade is desirably located on a forward or positive rake angle of two degrees to offset a blades tendency to rise during plowing.

The blade retention means secures the positioned blade against operational horizontal loads with the tie plates 26 and roller brace plates 40 serving to reinforce and distribute said loads amongst the remaining retention means structure. In particular the blade roller assembly 44 as shown in FIG. 2 will bear against the rearwardly located guide bar 24 while at the upper end of the blade the blade bar '52 will bear against the forwardly located upper roller assembly the intermediate length of the blade consisting of an arm of considerable length.

The invention having thus been described what we claim and desire to secure under a Letters Patent is:

1. A cable plow assembly for trailed close coupled attachment to a prime mover, said assembly including,

a guide box assembly connected to the prime mover by a hinged attachment in a closely spaced manner and adapted for swinging movement about an upright axis passing through the hinged attachment,

a cable plow blade adjustably carried in an upright manner within said guide box assembly for substantially vertical movement into desired penetration into the ground,

blade retention means including components aflixed to the sides of said plow blade and projecting laterally for engagement with additional blade retention components carried by said guide box assembly, said blade afiixed components including a blade roller assembly having roller shells disposed on opposite sides of said blade and elongate blade bars also disposed on opposite sides of the blade, said blade retention components carried by the guide box assembly including pairs of spaced apart guide bars on each side of the guide box with each pair receiving one of said roller shells therebetween for transfer of blade incurred loads to said guide box, additional blade retention components afiixed to the upper end of said guide box for load receiving engagement with said blade bars said blade affixed components and said components carried by the guide box assembly cooperating to allow said plow blade to be vertically adjusted within said guide box assembly even when said plow blade is subjected to horizontal loads, and

hydraulic cylinders interposed between said blade and the guide box assembly for vertical movement of the blade into desired ground penetration.

2. The cable plow assembly as claimed in claim 1 wherein said guide box assembly further includes upper and lower hinge brackets projecting horizontally forward for said hinged attachment to the prime mover, said bydraulic cylinders comprising a pair of upright cylinders oppositely disposed from the cable plow blade, said plow blade having a crosstree at its upper end for the reception of the piston rod ends of said cylinders whereby lengthwise movement is imparted to the blade.

3. The cable plow assembly as claimed in claim 2 wherein said cylinders are supported at their lower ends by said lower hinge bracket and said upper hinge bracket defines open areas for the passage of said cylinders therethrough.

References Cited UNITED STATES PATENTS 1,904,666 4/1933 Sack 61--72.7 2,325,896 8/ 1943 Waller 308-6 3,170,300 2/1965 Kelley 61-72.6 3,486,344 12/ 1969 Ylinen 6172.6

FOREIGN PATENTS 221,447 5/1962 Austria 61-72.6

DAVID J. WILLIAMOWSKY, Primary Examiner D. H. CORBIN, Assistant Examiner 

